Syntheses, X-ray crystal structures and urease inhibition of copper(II) and nickel(II) complexes derived from 5-bromo-2-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol

Abstract

Four new copper(II) and two new nickel(II) complexes, [Cu2(μ-Br)2L2] (1), [CuL(μ1,3-NCS)]n (2), [Cu2L2(μ1,3-N3)2] (3), [Cu3Cl2(μ-Cl)2L2] (4), [Ni3L2(μ2-η1:η1-OAc)2(μ2-η2:η1-OAc)2]·2CH3OH (5) and [NiL(μ2-1,5-dca)(OH2)]n (6), where L is the deprotonated form of 5-bromo-2-(((2-pyrrolidin-1-yl)ethyl)imino)methyl)phenol, dca is dicyanoamide, were synthesized and characterized by elemental analyses, infrared and electronic spectroscopy, and single crystal X-ray determination. The Cu atoms in complexes 1–3 and the outer two Cu atoms in complex 4 are in square pyramidal coordination, while the central Cu atom in complex 4 is in square planar geometry. The Ni atoms in complexes 5 and 6 are in octahedral coordination. The co-ligands bromide, thiocyanate, azide, chloride, acetate and dicyanoamide are interesting bridging groups in the construction of the polynuclear complexes with versatile structures. The urease inhibition assay indicates that the copper complexes have effective activities.